1. Field of the Invention
This invention relates to an ink tank having taken account of the correlation between an aqueous ink and an ink tank (inclusive of an ink tank with a recording head) which stores the aqueous ink therein in order to feed the same, and relates to a process for regenerating the ink tank. More particularly, it relates to an ink tank used in an ink jet recording method, and a process for regenerating such an ink tank.
2. Related Background Art
The ink jet recording method is a recording method involving applying a small ink droplet to any one of recording media such as plain paper and glossy media to form images, and has become rapidly widespread owing to a reduction in its cost and an improvement in its recording speed. Also, recorded materials thereby obtainable have made progress toward high image quality and in addition thereto digital cameras have rapidly come into wide use, users of ink jet printers now demand to output recorded materials which are comparable to silver halide photographs.
What is given as one requirement for how the recorded materials obtained by the ink jet recording method is comparable to silver halide photographs is that the recorded materials have a high fastness. Conventional ink jet recorded materials have a lower fastness than the silver halide photographs. Hence, there is a problem that, where recorded materials are exposed to light, humidity, heat, environmental gases present in air, and so forth for a long time, coloring materials on the recorded materials tend to deteriorate to cause changes in color tones or discoloration of images, i.e., the recorded materials have a low fastness. Many studies have been made in order to solve such a problem.
For example, a proposal is made in which the fastness is improved by the use of a coloring material having an anthrapyridone structure (see, e.g., Japanese Patent Application Laid-Open No. 2002-332419 and No. 2003-192930).
In recent years, it is also seen that a container called a refill kit whose ink tank in which an ink stored therein has been used and the ink stands used up is again filled with an ink is used by general users. As a countermeasure against environmental problems in recent years, the state of ink consumption is recorded in an information storage means such as a memory, or recorded in an ink tank itself. Such methods are known in the art (see, e.g., Japanese Patent Publication No. H05-019467 and No. 2004-009716). It is also put into practice that ink tanks in which inks have been used up are recycled.